Locking cyclinder

ABSTRACT

AN INEXPENSIVE TUMBER-TYPE LOCK IS PROVIDED BY A BARREL WITH AN AXIALLY ELONGATED TUMBER SLOT HAVING AN ELONGATED TUMBER ARRANGED FOR BOTH TRANSLATIONAL AND ROCKING MOVEMENT THEREIN. THE TWO MODES OF MOVEMENT OF THE TUMBER, COUPLED WITH SPRING BIAS MEANS WHICH TOGETHER WITH THE THRUST FORCE OF THE ENTERING KEY PROVIDES FOR A PITCHING MOVEMENT ON THE TUMBLER, YIELDS A SIMPLE AND INEXPENSIVE LOCK THAT PROVIDES THE SECURITY SOUGHT IN TIMBLER-TYPE LOCKS.

Nov. 16, 1971 J. F. WEBER, JR 3,620,056

LOCKING CYLINDER Filed Feb. 25, 1970 lNVIiN/UR. dOHN E WEBER UR.

A T TORNE Y United States Patent 01 ice 3,620,056 LOCKING CYCLINDER John F. Weber, Jr., Chicago, Ill., assignor to E. Edelmann & Co. Filed Feb. 25, 1970, Ser. No. 13,996 Int. Cl. Eh /14, 29/02 US. Cl. 70-362 6 Claims ABSTRACT OF THE DISCLOSURE An inexpensive tumbler-type lock is provided by a barrel with an axially elongated tumbler slot having an elongated tumbler arranged for both translational and rocking movement therein. The two modes of movement of the tumbler, coupled with spring bias means which together with the thrust force of the entering key provides for a pitching moment on the tumbler, yields a simple and inexpensive lock that provides the security sought in tumbler-type locks.

BACKGROUND OF THE INVENTION This invention relates to a lock-cylinder type of keyoperated lock wherein tumbler means which normally project outwardly of the periphery of the lock cylinders barrel must be brought into peripheral alignment with the exterior periphery of the cylinders barrel to permit unlocking.

Locks of the general type here involved normally use a plurality of reciprocating lock plates, or tumblers, with each lock plate biased to its projected position by a separate spring. The preferred number of tumblers in locks that afford at least some security is at least three. But use of so many tumblers and springs is relatively expensive and also presents assembly problemsv The reciprocating, tumbler-type locks are, furthermore, relatively easy to pick because the tumblers must be closely confined in their respective slots and each tumbler moves independently of neighboring tumblers. The picking of a lock utilizes the technique of independently retracting each tumbler to its retracted position while the other tumblers are being retracted and so held.

SUMMARY OF THE INVENTION AND OBJECTS The object of the present invention is to provide an improvement over prior lock-cylinder type locks in that the present locking cylinder utilizes only a single tumbler which is mounted and arranged so as to have two modes, or degrees, of motion in the tumbler slot, and with spring bias means arranged so that the single tumbler both translates and rocks in response to the resultant force derived from the spring bias and an entering key.

Another object is to provide a construction for a locking cylinder that is characterized by being easier to assemble, being less expensive by using less parts to achieve what is believed to be a desirable variety of interfitting code bits between the key and the tumbler means, and by being as sufliciently difficult to pick as a multiple reciprocatingplate type lock.

Further objects and advantages of this invention will become apparent as the following description proceeds and the features of novelty which characterize this invention will be pointed out with particularity in the claims annexed to and forming part of this specification.

A preferred embodiment of the invention is shown in the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a plan view of a lock cylinder that embodies therein the invention of this application;

FIG. 2 is an elevational view taken looking from the right of FIG. 1 with portions broken away to show certain details;

FIG. 3 is a cross-sectional view taken on line 33 of FIG. 1, at substantially the vertical plane through the longitudinal axis of the lock cylinder;

FIG. 4 is a cross-sectional view taken on line 4-4 of FIG. 1;

FIG. 5 is a cross-sectional view similar to the one shown in FIG. 3 showing the position of the lock tumbler when a key with the proper key code thereon is inserted into the lock cylinder to unlock the lock cylinder; and

FIG. 6 is a view similar to FIG. 5, but showing the position of the lock tumbler when a key that lacks the proper key code thereon is inserted into the lock cylinder, so that the lock cylinder remains locked.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, FIG. 1 illustrates generally at 10 a tumbler-type lock cylinder that is typically characterized by an axially-elongated cylindrical barrel 12 with an enlarged key-receiving head 14 at one end and a pair of bolt-retracting studs 16 at the other end. For purposes of clarity and so as to better emphasize the novel features herein, the typical mounting for the barrel and the bolts to which the cylinder connects have been omitted, except as partially indicated in FIG. 5. It is sufficient to note that the mounting for the lock cylinder comprises a cylindrical bore 18 in which the cylindrical barrel 12 is adapted to pivot once the tumblers therein are moved to a position where their outer edges are in alignment with the exterior periphery of the cylindrical barrel 12. Usually a pair of diametric grooves 20 are defined extending longitudinally of and opening through the periphery of the bore 18 and of a width to receive therein the radially outward portions of the tumbler that project outwardly of the cylindrical barrel 12. When a portion of the tumbler enters one or the other of grooves 20, the cylinder 10 is locked and cannot be rotated in bore 18. What has been disclosed thus far is well known in the art.

The cylindrical barrel 12 of this invention is provided with a longitudinal, key-receiving passage, or slot means, that includes entry slot 22a and tip slot 22b. The lower edges 23a and 23b of the slot means are in alignment for receiving thereon the straight edge of a key K, as seen in FIGS. 5 and 6. Between the said portions of the keyreceiving passage the barrel 12 is provided with a tumbler slot 24 that is axially elongated and of greater transverse width than the key-receiving passage. The tumbler slot 24 extends through the barrel 12, as best seen in FIG. 4, transversely of the barrels longitudinal axis. One portion of slot 24 is wider than the remainder for reasons appearing hereinafter.

A single tumbler 26 is positioned in tumbler slot 24. The tumbler 26 is a block-like member of a maximum axial length substantially equal to, but just slightly smaller than, the axial length of tumbler slot 24. The diametric size of tumbler 26 is substantially equal to the diameter size of barrel 12. The upper surface 28 and lower surface 30 are of the same cylindrical curvature as barrel 12. A longitudinal passage 32, of greater height than a key bit, is formed in one side of tumbler 26 and adapted to be moved into alignment with key-receiving passage means 22a and 22b. When aligned as in FIG. 5, the lower edge 32a of passage 32 is spaced below the lower straight edge of the key and below edges 23a and 23b, to permit pivoting of tumbler 26, as in FIG. 6.

The upper portion of tumbler slot 24, defined between spaced walls 24a and 24b, is wider than the portion between walls 24a and 240, thus defining an upwardly facing shoulder 24d that is to be engaged by an enlarged portion 26a of the tumbler to limit movement of the tumbler under bias of spring means that normally bias the tumbler toward a locking position. Flange means 26b serve to seat the lower end of a pair of coil springs 34, that are spaced axially of barrel 12 and which are under compression and which serve to bias the tumbler toward the FIG. 3 and 4 positions. The upper ends of springs 34 engage downwardly facing shoulder means 24c carried by barrel 12. While in the specific construction shown the size of the tumbler is greater at the top than at the bottom and the shoulder 24d is shown formed integrally with the barrel 12, it will be understood that both of these features could be varied to achieve the same end result with somewhat different structure.

To assemble the tumbler 26 in the barrel 12, the barrel is provided with a pair of bores, or passageways, 35 having the outline of shoulder means 242, but of greater dimension than shoulder means 242 to accommodate cocking of the tumbler as in FIG. 6. The two flanges 2612 are of a shape to enter and pivot in such bores 35. During assembly, the flanges 26b move to the position seen in FIG. 4, where shoulder 24d is abutted by tumbler part 26a. After springs 34 are entered in said pair of bores 35, material of the barrel 12 may be upset, or peaned over, to define shoulder means 24e which serve both as an abutment for the springs 34 and means to avoid dis-assembly. Instead of being formed in an upset operation, the shoulder means 246 may be provided by an insert piece, such as a bridging plug, separate screw heads, press fit parts, or the like.

The upper edge 36, of passage 32 through tumbler 26, is provided with an irregular key-code that must be matched by a similar edge 37 of the key of FIG. 5 in order to effect proper movement of the tumbler 26 to the unlocked position. In the event an improper key, K, is used, the combination, or resultant, of forces from the spaced springs 34 and the thrust of the entering key K operates, as in FIG. 6, to tend to move tumbler 26 in two manners, one manner transversely in the tumbler slot 24, or in the vertical plane through the longitudinal axis of the barrel 12, and the other manner pivotally about a fulcrum axis that lies perpendicular to the said plane. When tumbler 24 is moved as in FIG. 6, a portion extends outwardly of the periphery of barrel 12 and enters a groove 20, operating to keep the cylinder locked. It has been discovered that use of two axially spaced springs 34 located laterally of the tumbler and adjacent the axial ends of the tumber operates to apply forces to the tumbler at axially spaced points which rotate, pitch,

or pivot tumbler 26 more readily than if only one centrally-arranged, helical spring of circular cross section is used, although less satisfactory, but passable, results have been achieved with use of only a single spring. It is be lieved that a single helical spring of axially elongated periphery, such as of rectangular cross-section, would operate to also apply forces to the tumbler at axial spaced points.

In order to provide for the pitching of the tumbler 26, as illustrated in FIG. 6, the axial ends of the tumbler 26 are shaped, or bevelled, as shown, to provide fulcrum lines, or apices, 38 at the mid height of the tumber, at the ends of the greatest longitudinal dimension of the tumbler. The upright edge surfaces 40 on tumbler 26 taper or slope from the fulcrum lines 38 to the outer surfaces 28 and 30 of the tumbler 26, thereby providing relief means to accommodate tumbler pitching as seen in FIG. 6, while avoiding substantial longitudinal axial shifting of the tumbler 26 in the tumbler slot 24.

From the foregoing, it will be understood that tumbler 26, by being made to a size to slidably fit between wall pairs 24a-24b, and 24a-24c, is restrained from yawing, or wobble, relative to the longitudinal axis of the barrel 12, so as to insure axial alignment of key-entering passages 22a, 32 and 22b. At the same time, the tumbler 26 is free to reciprocate in directions perpendicular to the longitudinal axis of barrel 12 and to pitch, or pivot, about an axis that is perpendicular to the plane in which the number of parts in the lock have been reduced, the motion available to tumbler 26 simultaneously makes picking of the lock relatively diflicult and requires proper matching of key-codes between a key and the tumbler to effect unlocking of the lock-cylinder. At the same time the number of parts in the lock have been reduced, the size of the tumbler and springs have been increased making handling and assembly easier, and the overall cost has been reduced.

The key-receiving head 14 provides desirable features that are additionally useful in a lock of the type disclosed. Thus key-entry slot 22a communicates with an enlarged recess 42 in which abutment shoulder 44 of key K may rotate. The shoulder 44 engages surface 46 to limit penetration of key K and to axially locate key code 37 properly with respect to key code edge 36 on the tumbler 26. The head 14 may desirably be equipped with a radially movable shutter 48, for normally closing the entry to slot 22a. The shutter 48 is mounted to reciprocate in chamber 50, and a spring 52 biases the shutter to the overlying position of FIG. 2. An annular flanged metal part 54 provides an attractive trim and retains the spring 52. A cam-like recess 56 provides a guide for the entering tip of the key K to first displace shutter 48 and then enter slot 22a. A guide stud 58 provided on one upright side wall of slot 22a, spaced from lower edge 23a, is adapted to enter a longitudinal groove in the bit of key K to guide movement of the key into tumbler passage 32 while maintaining movement parallel to the edges 23a and 23b. If desired, a second guide stud 58' may be provided on the upright side wall of tip slot 22b.

While there has been shown and described a particular embodiment of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention and, therefore, it is intended in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a look cylinder of the type including an axially elongated barrel and tumbler means therein whose exterior periphery is to be moved into alignment with the exterior periphery of the barrel to permit unlocking of the lock, the improvement comprising, in combination, the barrel having an axially elongated tumbler slot extending through said barrel transversely of the barrels axis, an axially elongated tumbler in said tumbler slot, a key-receiving passage through said tumbler with an irregular key code provided along said passage, and means on said barrel and tumbler cooperating to provide the tumbler with freedom of movement in two different manners within a plane through the barrels axis, so as to require proper matching of a key with the key code to align the tumbler with the periphery of the locks barrel, axially extending key-slot means defined in said barrel, spring means normally biasing the numbler to a position where the irregular key-code surface on the tumbler is in position to be thrust against by a key moving axially into said key slot, and means on said tumbler and barrel providing fulcrum means spaced from the key-code surface on the tumbler, whereby the resultant of the forces from an entering key and said spring means provides a pitching moment on said tumbler about said fulcrum means.

2. A device as set forth in claim 1 wherein the tumbler is limited to movement in a single plane with one manner of movement being translation in opposite direction in said plane perpendicular to the longitudinal axis of the barrel and the other manner of movement being a rotational pitching about a non-fixed axis perpendicular to said plane.

3. In a lock cylinder of the type including an axially elongated barrel and tumbler means therein whose exterior periphery is to be moved into alignment with the exterior periphery of the barrel to permit unlocking of the lock, the improvement comprising, in combination, the barrel having an axially elongated tumbler slot extending through said barrel transversely of the barrels a-xis, an axially elongated tumbler in said tumbler slot, a key-receiving passage through said tumbler with an irregular key code provided along said passage, and means on said barrel and tumbler cooperating to provide the tumbler with freedom of movement in two different manners within a plane through the barrels axis, so as to require proper matching of a key with the key code to align the tumbler with a periphery of the locks barrel, the tumbler having a maximum axial length substantially equal to the length of the tumbler slot, at a point spaced between the radial outer surfaces of the tumbler, to provide fulcrums about which the tumbler may rock, and the axial ends of the tumbler being beveled to provide for a range ofrocking of the tumbler in the tumbler slot.

4. A device as in claim 1 including spaced guide elements on the barrel positioned for cooperation with parallel elements on a key to guide the key as it enters the key-receiving passage in the tumbler.

5. A device as in claim 1 wherein the spring means applies forces to the tumbler at points spaced axially of the barrel and adjacent the axial ends of the tumbler to effect application of a pitching moment to the tumbler until the key is fully passed through the key-receiving passage in the tumbler.

6. In a lock cylinder of the type including an axially elongated barrel and tumbler means therein whose exterior periphery is to be moved into alignment with the exterior periphery of the barrel to permit unlocking of,

the lock, the improvement comprising, in combination, the barrel having an axially elongated tumbler slot extending through said barrel transversely of the barrels axis, a single axially elongated tumbler in said tumbler slot, the maximum length of the tumbler being substantially equal to and only slightly smaller than the length of the tumbler slot, the axial ends of the tumbler being shaped to provide fulcrums at the ends of greatest longitudinal dimension of the tumblers a key-receiving passage through said tumbler with an irregular key code provided along said passage, and means on said barrel and tumbler cooperating to provide the tumbler with freedom of movement in two diiferent manners within a plane through the barrels axis including freedom to pitch longitudinally about a fulcrum at the end of the tumbler while the substantially equal lengths of the tumbler and tumbler slot restrain the tumbler from substantial axial movement, so as to require proper matching of a key with the key code to align the tumbler with the periphery of the locks barrel.

References Cited UNITED STATES PATENTS 1,360,622 11/1920 Crouch -365 2,766,611 10/1956 Hagel 70-364 FOREIGN PATENTS 324,128 8/1920 Germany 70-364 R 495,409 4/ 1930 Germany 70,366

1,019,379 10/1952 France 70-364 R ROBERT L. WOLFE, Primary Examiner US. Cl. X.R. 70364 R, 376 

